Random Access Memory (RAM)
RAM is the main memory of the computer. RAM provides permission to read and write over the memory chip. While the ROM permits only read permission, RAM is volatile by nature, which means that it needs continuous flow of electricity to keep its content safe. Otherwise, as soon as the power is off, the content in the RAM is lost. Therefore, due to its volatile
nature it is also referred to as temporary memory.
Various types of RAM are:
1. Dynamic RAM (DRAM): Is a form of semiconductor RAM. Dynamic RAM stores information in integrated circuits that contain capacitors. DRAMs are more commonly used than static RAMs even though they are slower. A DRAM can hold approximately four times as much data as a static RAM chip of the same complexity.
2. Static RAM (SRAM): Is a form of semiconductor memory. SRAM storage is based on the logic circuit known as a flip-flop, which retains the information stored in it as long as there is enough power to run the device. A static RAM chip can store only about one fourth as much data as a DRAM chip of the same complexity. It does not require refreshing and is usually much faster than DRAM. It is also more expensive. SRAMs are usually reserved for use in caches.
3. Rambus DRAM (RDRAM): Is a new powerful memory technology produced by Rambus Inc. It is very expensive RAM chip. It provides high data transfer speed; it can transfer data at up to 800 MHz.